Wire drawing and feeding apparatus

ABSTRACT

A wire drawing apparatus for use with a wire processing machine having an intermittently operated wire feed mechanism in which the wire drawing die is moved by a hydraulic actuator in a draw stroke to an extended position under the control of the wire processing machine, and the drawing die remains in the extended position until it is subsequently advanced with the wire by the feed mechanism of the processing machine so that the work stroke of the hydraulic actuator is automatically changed in accordance with the length of the wire advanced by the processing machine feed mechanism, and the cycling of the wire drawing apparatus is automatically varied in accordance with the cycle of the processing machine. Apparatus is also provided on the wire drawing machine for assisting the feed mechanism of the wire processing machine to advance the draw die and wire.

[15] 3,654,784 Apr. 11, 1972 [54] WIRE DRAWING AND FEEDING APPARATUS [72] inventors: Richard A. Alcock; Robert M. Guthrie;

Robert B. Johnston, all of Rockford, Ill.

[73] Assignee: Fastener Engineers, Inc., Rockford, Ill.

[22] Filed: Dec. 15, 1969 [21] Appl. No.: 885,198

[52] U.S. Cl ..72/5, 72/278, 72/285, 72/290 [51] Int. Cl ..B21d 55/00, B210 1/14 [58] Field of Search ..72/4, 5, 20, 274, 278, 279,

72/285, 290; 10/27 R, 12 R, 10 R [56] References Cited UNITED STATES PATENTS 3,290,916 l2/l966 Louis et al. ..72/290 2,797,799 7/1957 Ehlert ...205/1.2 3,260,085 7/1966 Mersek ....72/234 2,337,881 12/1943 Gaines ....72/332 3,260,084 7/1966 Mersek ....72/284 3,183,699 5/1965 I Ehlel't ....72/l61 3,260,086 7/1966 Prutton ..72/285 3,375,692 4/1968 Ware ..72/278 2,728,447 12/1955 Ware ..72/29O 2,880,854 4/1959 Friedman ..72/29O Primary Examiner-Charles W. Lanham Assistant Examiner-Michael J. Keenan Attorney-McCanna, Morsbach, Pillote & Muir [57] ABSTRACT A wire drawing apparatus for use with a wire processing machine having an intermittently operated wire feed mechanism in which the wire drawing die is moved by a hydraulic actuator in a draw stroke to an extended position under the control of the wire processing machine, and the drawing die remains in the extended position until it is subsequently advanced with the wire by the feed mechanism of the processing machine so that the work stroke of the hydrau lic actuator is automatically changed in accordance with the length of the wire advanced by the processing machine feed mechanism, and the cycling of the wire drawing apparatus is automatically varied in accordance with the cycle of the processing machine. Apparatus is also provided on the wire drawing machine for assisting the feed mechanism of the wire processing machine to advance the draw die and wire.

8 Claims, 6 Drawing Figures PATENTEDAPR 1 1 I972 sum 1 OF 3 wait mun (u:

PATENTEDAPR 11 I972 3, 654, 784

B an WIRE DRAWING AND FEEDING APPARATUS BACKGROUND OF THE INVENTION Wire processing machines generally embody their own stock feed mechanism which operate to intermittently advance a selectively adjustable length of stock in timed relation to the cutoff and forming operations performed by the processing machine. Such processing machines are generally adjustable as to the length of blank, size of wire, and speed of operation and it has been a problem to properly correlate the operation of cyclically operable wire drawing apparatus with the operation of the wire processing machine, under the varying operating conditions of the latter. In one common type of cyclically operable wire drawing apparatus which has heretofore been associated with wire processing machines, the wire is gripped by a set of stationary grippers and a movable draw die is moved in a draw stroke by a mechanically operated arrangement generally embodying a pivotally mounted draw lever. The draw lever is operated in timed relation with the processing machine, usually from a power takeoff from the processing machine to perform the draw stroke during the portion of the operating cycle of the processing machine during which the processing machine feed mechanism is dwelling. Substantial power is required to effect the drawing operation and the use of a power takeoff from the processing machine to operate the draw mechanism imposes a substantial load on the processing machine and, moreover, requires elaborate mechanical interconnection between the processing machine and wire drawing apparatus. This not only increases the initial cost of associating the wire drawing apparatus with the processing machine, but also makes it difficult to shift or move the wire drawing apparatus from one processing machine to another in the users plant. Moreover, some problems are encountered in adapting the wire drawing apparatus to the different blank lengths of the wire processing machine. The draw lever of the wire drawing machine must either be operated through a fixed stroke equal to or greater than the maximum blank length of the wire processing machine, in which event there is substantial lost motion between the draw lever and the draw die during a portion of each draw cycle which produces undesirable impact and pounding, or the stroke of the draw lever of the wire drawing machine must be adjusted each time the blank length of the wire drawing machine is changed, to change the draw stroke of the drawing machine in accordance with the blank length of the processing machine. However, even if the stroke of the draw lever of the drawing machine is adjusted, it is not possible to completely eliminate all lost motion and pounding between the draw lever and draw die of the drawing machine, since the stroke of the draw lever must be made at least slightly greater than the blank length to accommodate the slippage between the wire and the stationary grippers which inherently occurs during the draw stroke.

It has also been proposed to provide an hydraulically operated wire drawing machine in which a wire drawing unit including the wire grippers and draw die was supported so as to float axially along the wire. With this arrangement, the stroke and repetition cycle of the drawing apparatus is independent of the blank length and cycle speed of the processing machine and the drawing operation could be performed at any time during the dwell or feed portions of the operating cycle of the processing machine. However, when the feed mechanism of the processing machine operate to draw a length of wire, it not only must pull the wire but also the entire drawing unit including the wire grippers, hydraulic actuators, draw die and carriages therefor along with the wire. With such an arrangement, the inertia of the overall drawing unit is addition to that of the wire imposes a substantial load on the feed mechanism and blank length the adjusting mechanism of the processing machine, during starting and stopping of the feed operation.

An important object of the present invention is to provide a wire drawing apparatus associated with a wire processing machine in which the wire drawing apparatus is operated in timed relation with the processing machine under the control of the latter and automatically adjusts to changes in blank length and cycle speed in the processing machine without necessitating any adjustments by the operator to the wire drawing apparatus.

Another object of this invention is to provide a wire drawing apparatus for use with a wire processing machine, which does not impose heavy loads on the feed mechanism of the processing machine.

Yet another object of this invention is to provide a wire drawing apparatus for use with a wire processing machine which will automatically adjust the stroke of the drawing die to accommodate the slight backing up or lost motion between the wire and the wire grippers incident to cinching of the wire grippers on the wire during the draw operation, to assure accurate feeding of the desired blank length by the feed mechanism of the processing machine during the subsequent feed cycle.

Still another object of this invention is to provide a wire drawing apparatus for use with a wire processing machine which does not require mechanical interconnection between the drawing apparatus and the processing machine; which can be readily adapted to existing installations of wire processing machines; and which can be readily moved from one wire processing machine to another in the user's plant.

These, together with other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a wire drawing apparatus associated with a wire processing machine, with parts broken away and shown in section to illustrate details of construction;

FIG. 2 is a timing diagram which illustrates the timed relation of the movement of various parts of the wire processing machine and the wire drawing apparatus;

FIG. 3 is a plan view of the wire drawing apparatus with parts broken and shown in section to illustrate details of construction;

FIG. 4 is a side elevational view of the wire drawing apparatus;

FIG. 5 is a diagrammatic view showing the hydraulic control system for the wire drawing apparatus; and

FIG. 6 is a schematic wire diagram illustrating the electrical controls for the wire drawing apparatus.

WIRE PROCESSING MACHINE The wire processing machine designated generally by the letter P may be of any conventional construction embodying a wire or stock feed mechanism 10, a stock gauge 11 and a shear mechanism 12 and which is operable through an operating cycle including a feed portion during which the feed mechanism advances a length of wire against the gauge 11, and a dwell portion during which the shear mechanism 12 operates to shear a length of wire stock from the rod and transfer the same to one or more fabricating dies (not shown) wherein the severed blank is operated upon by the header 14. The particular processing machine disclosed herein is of the type more fully disclosed in the U.S. Pat. to Clouse No. 2,139,936 to which reference is hereby made for a more complete disclosure and description of its construction and operation. As more fully disclosed in that patent, the processing machine includes a main crank shaft 21 rotatably supported in a bed frame 22 and which carries a crank 23 connected through pitman 24 to a header slide 25 reciprocably mounted in guideway on the bed frame. Tools 26 carried by the header slide cooperate with fabricating dies (not shown) in the bed frame to effect the desired fabricating operations upon each of the sheared blanks. The main crank shaft 21 also carries a crank 28 which is connected through a crank follower 29 on a connecting rod 31 for operating the shear mechanism. As shown in the drawings and as more fully illustrated and described in the aforementioned patent, the connecting rod 31 has its forward end connected to a crank 32 secured to a cam shaft 33 supported in the bed frame. A cam 34 is secured to the cam shaft 33 and actuates a yoke 35 mounted on a shaft 36 in the bed frame, and which yoke is operatively connected to the vertically reciprocal shear blade 38. The feed mechanism is operated in timed relation with the header slide and shear mechanism and, as shown, the crank follower 29 is connected through a link 41 to a bell crank 42 mounted on a shaft 43 carried by the bed frame. A feed connecting rod 44 is adjustably connected to the bell crank 42 by adjustable mechanism 45 and the forward end of the feed connecting rod is connected to a wheel 46 which is coupled through an overrunning clutch (not shown) to one of the stock feed rolls 47. The other stock feed roll 48 is driven in unison with the feed roll 47 through suitable gearing (not shown) and, as is conventional, the feed rolls are grooved to receive the wire stock. The processing machine is operable through a cycle described in the aforementioned patent during which the various parts of the machine move as is shown in the timing diagram of FIG. 2 taken from the drawings in that patent. During each complete rotation of the crank shaft 21 or operating cycle of the machine, the mechanism operates to lower the shear plate 38 until the axis of the quill 38a in the shear plate is aligned with the stock passage 40, at which time the feed mechanism is operated to advance the stock through the passage 40 and quill passage 38a against the stock gauge 11. The length of stock fed by the feed rollers 47 and 48 is adjustable by the mechanism 45 and is customarily made slightly greater than the length of the desired blank to accommodate any retrograde movement that has occured in the wire stock during the preceding draw cycle and to assure that the stock is fed firmly against the stock gauge 11. The shear plate 38 is then raised to shear a blank from the stock and, after the blank has been severed from the stock, the severed blank is ejected from the quill 38a into a transfer carriage (not shown) which transfers the sheared blanks successively through the fabricating dies, all in a manner more fully disclosed in the aforementioned patent. The header is reciprocated during the operating cycle so that the tools carried by the header can effect the desired fabricating operations on the sheared blanks.

WIRE DRAWING APPARATUS The wire drawing apparatus designated generally by the numeral D is operated under the control of the wire processing machine P to effect the drawing operation during the portion of the operating cycle of the processing machine in which the feed mechanism 10 dwells. In general, the drawing apparatus includes a base 51, stationary wire gripper means 52 mounted on the base adjacent the outlet end of the machine, a draw die 53 mounted for reciprocation longitudinally of the wire W toward and away from the stationary grippers 52, and hydraulic actuator mechanism 54 which is operated under the control of the processing machine to move the draw die to an extended position away from the stationary grippers in a draw stroke, and to then allow the draw die to dwell in its extended position until the feed mechanism 10 on the processing machine advances the wire W in a subsequent feed cycle. The maximum stroke of the hydraulic actuator mechanism is made greater than the maximum length of stock to be fed by the processing machine feed mechanism 10, during any cycle of operation. However, the hydraulic actuator mechanism only operates to move the draw die to a preselected extended position and the timingand distance of retraction of the draw die and the hydraulic actuator members connected thereto is effected under the control of the feed mechanism 10 of the processing machine so that the effective working stroke of the hydraulic actuator automatically adjusts in accordance with the length of stock fed by the feed mechanism. Accordingly, when changing. the length of blank or cycle speed, it is only necessary to adjust the position of the work stop 11 in the processing machine and the cycle speed of the processing machine, and the wire drawing machine automatically adjusts to the change in blank length and cycle speed. Moreover, the drawing apparatus automatically compensates for the slight slippage or lost motion between the wire and the stationary gripper dies which occurs during cinching of the gripper dies on the wire during the draw stroke.

The base 51 of the wire drawing apparatus can be of any suitable construction and, as best shown in FIG. 1, includes longitudinal frame members 61 connected at their ends by cross members 62, which frame members and cross members are preferably supported for vertical adjustment on legs 63 to accommodate processing machines of different size. In the form shown this is achieved by providing leg sections 63a on the cross members which are vertically adjustably clamped to the legs 63 as by clamp plates 63b.

A crosshead 65 is mounted at one end of the base and the stationary wire gripper jaws 52 are mounted in a jaw holder on the crosshead 65. As best shown in FIG. 3, the crosshead 65 has a pocket 66 which forms a jaw holder and the wire grippers 52 are in the form of wedge shaped gripping jaws 52a disposed between guide members 52b having relatively converging guide faces. Antifriction elements such as rollers 52c are preferably provided to facilitate movement of the gripping blocks into and out of wire gripping position. The gripping jaws have wire receiving grooves 52d on the registering faces and the jaws are arranged so as to move into wire gripping position to hold the wire against retrograde movement during movement of the draw die 53 in a draw stroke, that is to the right as viewed in FIG. 3, and to release the wire when the wire is advanced by the feed mechanism 10, that is to the left as viewed in FIGS. 3 and 4. A gripper biasing spring assembly 67 is mounted on the crosshead 65 and engages the grippers 52 to spring load the grippers toward their wire gripping position.

The draw die 53 is mounted for movement lengthwise of the wire toward and away from the stationary grippers 52 and for this purpose guideways 68, conveniently in the form of rods, are mounted on the base and supported at one end on the crosshead 65 and at the other end on a crosshead 69 carried by the base. The draw die 53 is mounted on a carrier 71 which is slidably supported on the guide rods 68 for movement toward and away from the draw die and fixed stops 72 are provided to limit maximum extension of the draw die away from the stationary gripper 52. Provision is made for lubricating the wire as it enters the draw die and, in the form shown, a lubricant box 73 is mounted on the carriage 71 at the inlet side of the draw die. The lubricant box has a wire inlet opening 73a in alignment with the draw die to allow the wire stock to pass through the lubricant box into the draw die. A wire guide bushing 74 is preferably provided on the carriage at the outlet side of the draw die for guidably receiving the wire and to aid in straightening any slight tendency of the wire to curve or deflect due to any imperfection in the die or the mounting therefore.

The hydraulic actuators 54 are connected to the movable carriage 71 and to the frame to move the carriage. A pair of hydraulic actuators are herein shown disposed at relatively 0pposite sides of the wire to be drawn and each includes cylinder and piston actuator members designated 75a and 75b. As best shown in FIG. 3, the cylinder members 750 are mounted as by mounting brackets 76 on the stationary crosshead 65 and the piston actuator members 75b are connected at 77 to the movable carriage 71. Hydraulic manifolds 78a and 78b interconnect the cylinders 75a and at opposite sides of the piston therein so that both hydraulic actuators are operated in unison. A high force is required to move the draw die in a draw stroke, which draw force is approximately equal to the area reduction of the wire by the draw die times the tensile strength of the wire times a factor of about 2 and may exceed 6,000-8,000 pounds for wire of the order of to 1 inch in diameter. The hydraulic control system, described hereinafter, is arranged to apply motive fluid pressure, that is fluid pressure which when applied to the draw die, is sufficient to move the same to effect a draw stroke. As previously described, the hydraulic actuators 54 operate under the control of the processing machine P to move the draw die in a draw stroke to a preselected extended position and retraction of the draw die is effected in response to feeding of the wire W by the feed mechanism on the processing machine. It is generally desirable to minimize the force which must be exerted by the feed mechanism on the wire to advance the same, in order to minimize marring of the drawn wire by the feed mechanism and to also minimize the load on the feed mechanism. In the present wire drawing machine, the force required to advance the wire includes a component due to the frictional resistance or drag of the carriage 71 on the guideway 68, as well as a component due to the frictional resistance or drag of the piston members 7512 in the cylinder member 75a and in the packing glands on the cylinder members. Moreover, an infeed straightening device such as shown at 81 is commonly provided on wire drawing machines to straighten the wire prior to entry into the draw die, and these straightening devices impose a further drag on the advancing wire. In addition, some force is necessary to pull the wire off the supply coil. In the preferred embodiment shown in the drawings, the wire drawing apparatus is provided with a wire feed assist mechanism for assisting advance of the draw die and carriage along with the wire without, however, interferring with the length of feed or the timing of the feed of the wire by the feed mechanism on the processing machine. In general, the feed assist mechanism is arranged to apply a biasing force to the carriage 71 in a direction to yieldably urge but not move the same toward the stationary grippers 52, and the biasing force applied to the carriage is made selectively adjustable so as to substantially compensate for the frictional drag of the carriage 71 and piston actuator members 75b, and to also compensate for the resistance or drag imposed on the wire by any straightening mechanism such as 81 which may be utilized with the drawing apparatus. The assist mechanism is of the fluid actuated type and the pressure, herein referred to as the biasing fluid pressure, is selectively adjustable so that the biasing force applied by the assist mechanism to the carriage is sufficient of itself to advance the carriage and wire W, until the feed mechanism 10 on the processing machine operates during the feed portion of the operating cycle. Separate fluid actuators are preferably provided and, as shown, a pair of linear fluid actuators 82 including cylinder actuator members 82a and piston actuator members 82b are symmetrically mounted on relatively opposite sides of the path of the wire W. The cylinder actuator members 820 are herein shown mounted by brackets 84 on the stationary crosshead 65 and the piston actuator members 82b are connected at 85 to the movable carriage 71. Apparatus described hereinafter is provided to apply a regulated biasing fluid pressure to the actuators 82 to yieldably bias the same in the direction of advance of the carriage 71.

Apparatus is also provided in the drawing machine to facilitate starting of the wire to the drawing machine and, for this purpose, push point grippers 91 are provided at the inlet side of the wire drawing machine. The push point grippers are selectively movable to an operative position for gripping the incoming wire to hold the same while the draw die 53 is pushed over the end of the wire through successive strokes until a sufficient length of wire has been push pointed to reach the stationary wire grippers 52. At that time, the push point grippers 91 are released and the drawing machine is operated in its normal fashion. As best shown in FIG. 3, the push point grippers 91 are mounted on the crosshead 69. The crosshead has a pocket or cavity 92 formed therein for receiving wedged shaped gripper blocks or jaws 91a and guide blocks 93. The guide blocks 93 have inclined guide faces 93a engageable with the wedge shaped gripper blocks and arranged to urge the latter into gripping engagement with the wire to prevent retrograde movement of the wire, while releasing the wire to allow advance of the same. As shown in FIGS. 1 and 3 the gripper blocks 91a have wire receiving grooves 91b on their registering faces which operate to grip the wire when the guide blocks 93 are in the position shown in FIG. 3. The guide blocks 93 are releasably held in their operative position shown in FIG. 3, as by removable pins 95 adapted to extend through aligned openings in the top plate 96 and guide blocks 93. The pins 95, however, can be removed to allow the guide blocks 93 to move outwardly into their inoperative position during normal operation of the wire drawing machine. In order to facilitate guiding of the pointed end of the wire from the draw die 53 to the stationary grippers 52, a guide tube 98 is advantageously provided and extends from the stationary crosshead 65 to a point adjacent the ends of the actuator cylinders 75a to guide the pointed end of the wire into the stationary grippers.

The wire straightening device 81 is mounted at the inlet end of the wire drawing apparatus as by a bracket 101. The number and configuration of the straightening rolls in the wire straightening apparatus can be varied as is well understood in the art and, in the embodiment shown, the straightening apparatus is of the three-roll, single-plane type which includes a pair of lower straightening rolls 102a and 102b and an upper straightening roll 103 located intermediate the lower rolls. One of the rolls such as the upper roll 103 is adjustably mounted as by guide blocks 104 (FIG. 4) in a vertical guideway 105. A selectively operable fluid actuator 106 is provided for urging the upper straightening roll 103 into its operative position and an adjustable mechanism such as a screw 107 is arranged to engage the block 104 to limit downward movement of the roll 103 to the proper level for straightening the stock. Vertical and lateral inlet guide rollers 108a and 10811 are conveniently provided at the inlet of the wire straightening apparatus to guide the stock into the straightening rolls. The fluid actuator 106 includes cylinder and piston actuator members 106a and 10612 and apparatus described hereinafter is provided for applying a regulated pressure to the actuator 106 to pressure load the upper straightening roll 103.

An hydraulic circuit is shown in FIG. 5 for supplying motive fluid pressure to the hydraulic actuators 54 of a magnitude to effect drawing of the wire, during the dwell of the feed mechanism 10 of the wire processing machine. The hydraulic control circuit interrupts application of motive fluid pressure to the hydraulic actuators after the draw die reaches a preselected extended position, and feeding of the wire and return of the draw die is effected by the feed mechanism 10 of the wire drawing machine aided by the feed assist mechanism, so that the stroke of the hydraulic actuators is automatically adjusted in accordance with the length of wire fed by the feed means 10. In addition, the hydraulic circuit disclosed in FIG. 5 is advantageously arranged so as to supply the variable amount of fluid utilized in operating the hydraulic actuators with different strokes and cycle speed, without requiring any adjustment by the operator. Fluid pressure is supplied by a pump 110 driven by a motor 111. The pump has its inlet 110a connected through a filter 113 to a reservoir 114 and an outlet 1101: connected to a delivery line 115. A two-position flow control valve 116 is provided for controlling flow of fluid from the pump to the fluid actuators 54 and has inlet ports 116a and 116b respectively connected to the pump delivery line 115 and to a return line 117. The valve 116 also has controlled outlet ports 1160 and 116d which are connected through lines 121 and 122 to the manifolds 78a and 78b on the fluid actuators. As diagrammatically illustrated in FIG. 5, lines 121 and 122 include flexible hose portions 121a and 122a intermediate the valve 116 and the manifolds. The valve 116 is of the twoposition type and is operative in one position to supply fluid under pressure from the pump delivery line 115 to the line 121 to extend the fluid actuators and move the draw carriage 71 in a draw stroke. During the draw stroke, the rod end of the fluid actuators is vented through valve 116 and line 117 to a reservoir. Valve 116 is operative in the other positions thereof shown in FIG. 5 to interconnect the lines 121 and 122 with each other and with the return line 117 to the reservoir 114 and thereby allow the piston actuator members 75b to hydraulically float in the cylinder actuator members 75a. Thus, in the position shown in FIG. 5, valve 116 equalizes the pressure at opposite sides of the piston members 75b of the fluid actuators so that the fluid actuators are not operative to move the draw carriage 71. However, since the valve 116 does interconnect the lines 121 and 122 with each other and with the reservoir 114, the draw carriage is free to be retracted during the subsequent feed cycle of the processing machine, with the fluid at the blind end of the actuator cylinder 75a flowing in part to the rod end of the actuator cylinder and the remainder passing back to the reservoir through the return line 117.

The rate of consumption of fluid by the hydraulic actuators 54 varies with the length of the draw stroke and the cycle speed of the processing machine and provision is made for accommodating the varying requirements of the hydraulic actuators. In the preferred embodiment disclosed, the pump is of the positive displacement, constant-volume type and an accumulator 130 is used in conjunction with a check valve 133 and a pilot operated unloading valve 134 to automatically accommodate the varying requirements of the hydraulic actuators. As shown in FIG. 5, the accumulator 130 is connected through a line 131 to the pump delivery line 115 and the check valve 133 is located in the pump delivery line 115 intermediate the pump outlet 110b and the connection of the accumulator line 131 and arranged to prevent flow of fluid from the accumulator 130 back to the pump, while opening to permit flow from the pump to the accumulator and valve 116. The pilot operated unloading valve 134 has its inlet 134a connected to the pump delivery line 115 intermediate the check valve 133 and the pump outlet 110b, and the outlet 134b of the unloading valve is returned to the reservoir 114 through a filter 118. The unloading valve is pilot operated and has a pressure control line 1340 connected to sense the pressure in the accumulator and in the portion 115a of the delivery line 115 after the check valve 133. The pilot operated unloading valve is arranged so that when the system pressure reaches a preselected upper pressure limit, for example 1,000 p.s.i., the valve opens and allows the fluid from the pump to return to the reservoir at a relatively low pressure, for example 75 psi. The accumulator charge is maintained by the check valve 133 and when the system pressure (after the check valve 133) drops to the lower pressure setting of the unloading valve, for example 850 p.s.i., the valve closes and allows the pump to recharge the accumulator and deliver fluid to the actuators, if they are being actuated at that time. The size of the accumulator 130 is selected so as to be greater than and preferably at least several times the maximum volume displacement of the.

pair of fluid actuators 54 and may be of the gas-charged type having a movable wall 130a to separate the fluid chamber 130b from the gas charging chamber 130C. A drain line and valve 130d is provided to enable draining any fluid that leaks past the piston into the gas chamber. A two-position valve 141 is provided for unloading the accumulator, when desired and, as shown, valve 141 is connected through line 142 to the accumulator line 131 and has an outlet 143 connected to the reservoir 114. The valve 141 was normally urged to its open position and an actuator such as a solenoid 140a is provided for moving the valve 141 to its closed position. A pressure gauge 144 is conveniently provided and connected to the pump delivery line after the check valve 133 to indicate the pressure in the accumulator. In order to protect the gauge, a two-position on-off valve 145 is conveniently provided in the line between the gauge and the accumulator.

Valve 116 is automatically operated under the control of the wire processing machine to move the draw carriage in a draw stroke and is conveniently electrically actuated as by actuator 1162. A pressure compensated flow control valve is preferably provided in the delivery line 115 after the check valve 133 to control the rate of movement of the fluid actuators 54 during the draw stroke. As diagrammatically shown, the pressure compensated valve 140 has a flow control valve 140a and the pressure drop across an orifice 140d in the line is applied to valve actuators 14% and 1400 to variably restrict flow through valve 140a in a manner to maintain a preset pressure drop across the orifice 140d corresponding to the desired rate of flow in line 115. The pressure compensated flow control valve is selected and adjusted to maintain a flow rate sufficient to accommodate the volumetric displacement of the pair of hydraulic actuators 54 within the draw portion of the operating cycle of the processing machine.

The hydraulic circuit also includes means for moving the hydraulic actuators to enable push pointing of the wire. During push pointing, the hydraulic actuators 75 are operated to extend and retract the draw die through successive strokes until the length of wire which has been pushed pointed is sufficient to reach the stationary grippers 52. In the circuit illustrated in FIG. 5, a separate manually operable valve 151 is provided for reversibly supplying hydraulic fluid to the actuators 75 during push pointing, and means is provided for shutting off flow to and from the valve 116 during the push pointing operation. This latter means includes a pair of pilot operated check valves 152 and 153 disposed in the lines 121 and 122. The pilot operated check valves are arranged to close to prevent flow from the lines 121 and 122 back to the valve 166 and a two-position pilot control valve 154 is provided for actuating both the pilot operated check valves to their open position. As shown, the pilot control valve 154 has its inlet 1540 connected to the delivery line and its controlled outlet l54b connected to the operators of the pilot operated check valves 152 and 153. Valve 154 is normally positioned to vent the pilots to the reservoir 114 and is selectively operable as by an electroresponsive actuator 154d to its open position pressurizing the pilot operated check valves to their open position.

The manually operable push pointing valve 151 is herein shown of the three-position flow reversing type having a center shut-off. The valve has a supply inlet line 1510 connected to the pump delivery line and an outlet 1511; connected to the reservoir 114. The valve also has controlled outlets 151C and 151d connected to the lines 121 and 122 leading to the opposite ends of the fluid actuator cylinders 75a. When the valve 151 is in its mid-position shown, it blocks both controlled outlet ports so that the hydraulic actuators can be controlled by the control valve 116. Valve 151 is movable from its midposition to alternately supply an exhaust fluid from the actuators 75 to thereby extend and retract the draw carriage during the push pointing operation.

The feed assist actuators 82 are preferably pneumatically operated and, as illustrated in FIG. 5, air is supplied from a air supply S through a filter 161, adjustable pressure regulator 162, lubricator 163 and check valve 164 to an air receiver 165. The air receiver is connected through a line 166 to a twoposition valve 167 having its outlet connected through a line 168 to the cylinders 82a at one side of the piston member 82b. The regulator 162 is adjusted to supply air at a preselected pressure to the actuators and the receiver operates to maintain a substantially constant pressure on the fluid actuators 82 throughout their stroke to provide a substantially uniform force to aid in moving the draw carriage during the feed stroke of the processing machine feed mechanism 10. The valve 167 is an on-off valve which is normally positioned to supply fluid actuators 82 and which is operative in its other position to block line 166 and vent fluid from the actuators 82. An electroresponsive operator 1670 is conveniently provided for moving the valve 167 to its vent position. As shown, a receiver vent valve 169 may be provided for venting the air receiver 165, and gauges 171 and 172 are herein shown for indicating the pressure in the receiver and at the outlet of the regulator 162 respectively. Air is also'supplied through a line 174 and two-position valve 175 to the fluid actuator 106 to pressure load the straightening roll into its operative position.

Reference is now made to the electrical control circuit illustrated in FIG. 6. As shown, the pump drive motor 111 is connected through conductors 181, motor start relay contacts a and conductors 183 to a main disconnect switch 184 which controls application for power from conductors 185. A low voltage control circuit including conductors 186 and 187 is connected through a transformer 188 to the main power conductors 183 and, when the main disconnect switch 184 is closed. power is applied through transformer 188 to the control circuit conductors 186 and 187. However, the pump drive motor 111 remains deenergized until the motor start relay contacts 1950 are closed. The control circuit includes a motor start circuit having a normally closed stop switch 191 connected tin series by conductor 192 to a normally open motor start switch 193. The start switch is connected through conductor 194 to a motor start relay 195 that is otherwise connected to control circuit conductor 187. When the normally opened start switch 193 is closed, the motor start relay 195 is energized and closes the normally open motor start relay contacts 195 a. An indicator lamp 196 is conveniently connected in parallel with the motor start relay 195 as by conductors 197 to indicate when the pump drive motor is energized. In addition, a main control relay 198 is connected by conductors 199 and 194 in series with the motor start and stop switches 193 and 191 so as to also be energized when the motor start switch is closed. Main control relay 198 operates to close relay contacts 1980 which are connected in parallel by conductors 200 with the motor start switch 193 to establish a holding circuit which maintains the motor start relay 195 and control relay 198 energized when the start switch 193 is opened, and until the stop switch is thereafter operated to deenergize the start circuit. The accumulator unloading valve 141 is also operated to its closed position when the pump drive motor 111 is energized and, for this purpose, the actuator 141a for the unloading valve is connected through conductors 201 and 194 in a series circuit with the motor start and stop switches 193 and 191 so as to be energized upon closing of the start switch.

Operation of the main control relay 198 also closes relay contacts 19811 to establish a circuit from conductor 186 to conductor 203 leading to the circuits for controlling push pointing operation and automatic operation of the wire drawing apparatus. One manually operable dual switch including normally opened switch 204a and normally closed switch 204b is provided for conditioning the hydraulic circuit for push pointing operation and a second manually operable dual switch including normally closed switch 205a and normally open switch 205b is provided for conditioning the hydraulic circuit for automatic operation under the control of the wire processing machine. Switch 204a is connected through a conductor 206 to the conductor 203 and is otherwise connected in series with normally closed switch 205a and conductor 207 to a push pointing control relay 209 to energize the relay 209 when the normally open switch 2040 closed. Relay 209, when energized, closes relay contact 209a connected by conductors 210 in parallel with the switch 204a to establish a holding circuit to maintain the relay 209 energized when the manually operable switch 204a is released. The actuator 167a for the air assist control valve 167 is connected as by conductors 211 in a series circuit with switch elements 204a and 205a. Actuator 167a is operative, when energized, to move the air assist control valve 167 to its unloading position to unload the air assist cylinders 82a.

Normally closed switch 204b is connected through conductor 213 to conductor 203 and is connected in series with the normally opened switch 205b and the through conductor 214 with the automatic operation control relay 215. Relay 215 operates when energized to close relay contacts 215a which are connected in parallel to conductors 216 with the normally opened switch 205b to establish a holding circuit for that switch. An indicator lamp 217 is conveniently connected in parallel with the relay 215 as by conductors 218 to indicate when the control circuit is in automatic operating condition. The actuator 154d for the pilot control valve 154 is connected in series with a normally opened switch 221 and through conductor 222 to conductor 214. Switch 221 is positioned to sense the drawn wire as it emerges from the draw die 53 and, as shown in FIG. 3, is mounted on the draw carriage at the outlet side of the draw die to be closed when the stock extends through the draw die and to open when the end of the stock passes from the draw die and past switch 221.

The automatic control relay 215 also operates to close relay contacts 215b to establish a circuit from conductor 203 to conductor 224, normally closed switch 225. cam operated switch 226, and conductor 227 to the actuator l16e for the control valve 116. Cam control switch 226 is normally closed and is operated by a cam 231 driven in timed relation with the wire processing machine, as by the chain drive 232 to the main crank shaft 21 as shown in FIG. 1. The timing of the cam 231 is correlated with the operation of the processing machine feed mechanism 10 and cutoff mechanism 12, and cam 231 is preferably arranged so as to close switch 226 shortly after the cutoff mechanism has been operated to sever a blank from the wire stock and to open just prior to operation of the feed mechanism 10 to advance the succeeding length of stock. The valve 116, when energized, supplies fluid under pressure to the hydraulic actuators to move the same to an extended position. In order to avoid the heavy impact of the draw carriage against the stops 72 when the draw carriage is moved to its extended position, the normally closed switch 225 is provided and positioned as shown in FIG. 4 so as to be operated by the draw carriage, when the draw carriage reaches a position somewhat in advance of the stops 72, to shut off the application of hydraulic power to the actuators 54. There is some overtravel of the carriage after opening the switch 225 and the switch is positioned sufficiently in advance of the carriage stop 72 to minimize if not eliminate mechanical impact of the carriage against the stops.

OPERATION From the foregoing it is thought that the construction and operation of the machine will be readily understood. Briefly, starting of the machine is effected by closing a normally opened start switch 193 to effect energization of the pump drive motor 111, master control relay 198 and actuator 141 for the accumulator unloading valve, to close the valve 141 to allow the accumulator pressure to build up to the desired maximum value, for example 1,000 p.s.i. When starting a length of wire to the machine, it is necessary to push point the length of wire sufficient to extend to the stationary grippers 52. Manual operation of the dual switches 204a and 204b respectively close a circuit to the push pointing relay 209 and open the circuit to the automatic control relay 215. When the push pointing relay 209 is energized, it establishes a holding circuit by closing relay contacts 209a. In addition, closing of switch 204a energizes the actuator 167a of the air assist unloading valve 167 to unload the air assist actuators 82. Moreover, opening of switch 204b assures that the actuators 154d for the pilot control valve 154 is deenergized so that the pilot control valve can close and allow check valves 152 and 153 to close. Under these conditions, manually operable push pointing valve 151 can be operated under the control of its handle to selectively extend and retract the draw carriage. During the push pointing, pins are positioned in the openings in the guide blocks 93 to hold the guide blocks in their operative position. The push pointing grippers 91 operate to grip the stock and hold the same during the drawing operation and to release the stock when the draw die is retracted, and push pointing is continued until the draw die has been manually cycled through a number of strokes to push point a length of wire sufficient to extend to the stationary grippers 52. At that time the manually operable push point valve 191 is returned to its neutral position blocking the controlled outlet ports l51c and 151d, and the guide blocks for the push point grippers are moved to their inoperative position so that the push point grippers 91 release the wire. It is preferable to effect the push pointing operation at a substantially lower speed than the normal drawing operation and for this purpose the manually operable valve is selected so that the flow rates through the valve operate the actuator at the desired lower speed.

Automatic operation is effected by manually operating the dual switches to open switch 205a and close switch 205b. Opening of switch 205a deenergizes the push point relay 209 and the actuator 1670 for the valve 167 to allow the same to return to its normal position shown in FIG. supplying pneumatic pressure to the assist actuators 82. Closing the switch 205b energizes the automatic relay 215 which closes contacts 215a to establish a holding circuit and which also closes contacts 215b to energize the automatic control relay 215. Thereafter, operation of the wire drawing apparatus is under control of the wire processing machine P. The draw die carriage is shown in extended position in the drawings and, as the stock feed mechanism of the processing machine is driven, it advances the wire and pulls the draw die carriage and actuator piston 75b with the wire until the wire engages the stop gauge 11 in the processing machine. As is customary, the wire feed mechanism is adjusted so as to advance a length of wire slightly greater than the desired length of the blank to accommodate any slippage between the feed mechanism and the wire stock and to compensate for the slight back movement of the wire stock which occurs during the drawing operation. When the wire stock engages the stock gauge 11, retraction of the drawing die is interrupted and the draw die carriage remains in this position until after the processing machine has moved the shear blade 38 to cut off a blank from the stock. The cam 23] is timed so as to close the switch 226 shortly after cut off in the processing machine. Closing of the switch 226 establishes a circuit to the actuator 116e for the flow control valve 116 to supply fluid under pressure to the hydraulic actuators 82. This effects extension of the hydraulic actuators at a rate controlled by the pressure compensated flow control valve 140, until the carriage approaches its extended position and operates the switch 225 to open the same. Opening of switch 225 deenergizes the actuator 116e and allows the control valve 116 to move to the position shown in FIG. 5 interconnecting the lines 121 and 122 to opposite ends of the actuator cylinders 82a with each other and with the return line 117. There is a slight overtravel of the carriage 71 after shutoff of the valve 116 and the carriage remains in this extended position until the subsequent feed cycle of the wire processing machine. During the feed cycle, the feed mechanism 10 of the processing machine draws the length of wire assisted by the assist actuators 82, until the end of the wire stock again engages the stock gauge 11.

The processing machine thus automatically controls the cycle speed of the wire drawing machine and, since the return of the draw carriage and the hydraulic actuator pistons 75b is effected under the control of the feed mechanism of the processing machine, the length of the stroke of the wire drawing machine and of the hydraulic actuator cylinders is automatically controlled by the length of stock fed by the feed mechanism during the preceding feed cycle. The amount of oil consumed during the draw cycle will vary with the length of the draw stroke and with the cycle speed. However, during automatic operation, the pump 110 operates to fill the accumulator 130 until the precharge pressure equals the setting on the unloading relief valve 134. At that time, the relief valve opens and dumps the pump delivery until the precharge pressure drops a set amount, for example percent from its maximum value. The unloading relief valve then closes and loads the pump and starts to refill the accumulator again. With this arrangement, a constant delivery pump can be utilized to accommodate the varying demand by the drawing apparatus, without producing excessive heating of the hydraulic fluid. The unloading relief valve, when opened, relieves the pump delivery pressure to a relatively low value so that the heating of the hydraulic fluid is minimized under these conditions.

We claim:

1. In combination with a wire processing machine operable through an operating cycle and having feed means, means for intermittently driving the feed means to advance a selectively adjustable length of drawn wire during a draw portion of the operating cycle and for interrupting advance of the wire during a subsequent dwell portion of said operating cycle, a wire drawing apparat'us operable in timed relation with said processing machine to draw a length of wire during the dwell portion of said operating cycle correlative with the length of wire advanced by said feed means during the feed portion of said operating cycle, said wire drawing apparatus including a frame, a movable carriage mounted on said frame for movement toward and away from said feed means, draw die means on said movable carriage, a stationary head on said frame and wire gripper means on said stationary head between said draw die means and said feed means for gripping the wire to inhibit movement of the wire in a direction opposite the direction of advance by the feed means, hydraulic actuator means including a cylinder actuator member and a piston actuator member in said cylinder actuator member, said hydraulic actuator means having one of said actuator members connected to said movable carriage for movement therewith and the other anchored to said frame means, an hydraulic fluid reservoir, hydraulic fluid pressure supply means, control valve means connected to said reservoir and to said hydraulic fluid pressure supply means and to said cylinder actuator member, said control valve means having passage means operative in a first position of the control valve means to supply motive fluid pressure from said hydraulic fluid pressure supply means to said hydraulic actuator means sufficient to move the carriage and draw die in a draw stroke only, said control valve means having passage means operative in a second position of said control valve means to interrupt application of motive fluid pressure to said hydraulic actuator means and to hydraulically connect the actuator means to allow the piston actuator member to float axially within cylinder actuator member, means controlled by said processing machine for moving said control valve means to said first position thereof during said dwell portion of said operating cycle to supply motive fluid pressure to said hydraulic actuator means sufficient to move said carriage and draw die in a draw stroke only, means operative after said carriage and draw die reach a preselected extended position to move said control valve means to said second position thereof to allow the draw die and carriage to dwell in their extended position until the subsequent feed portion of said operating cycle, said feed means being operative during said feed portion of said operating cycle to advance the drawn wire a selected distance and move said draw die means and said carriage and said one of said actuator members with the wire in a direction away from said extended position whereby the working stroke of said actuator means is automatically adjusted in accordance with the distance the wire is advanced by said feed means and the operation of the actuator means is automatically timed with the cyclic operation of the feed means.

2. The combination of claim 1 including a set of push point grippers on said frame at the inlet side of said drawing die means selectively operable to grip the wire to hold the same against retrograde movement, a second control valve means operable to reversibly supply motive fluid pressure to said hydraulic actuator means to effect movement of the carriage and drawing die means in push point drawing and return strokes, and means for rendering said first mentioned control valve means inoperative to supply motive fluid pressure to said actuator means during push pointing of the wire.

3. The combination of claim 1 including means for sensing the wire exiting from the draw die means, and means responsive to said wire sensing means for moving said control valve means to said second position thereof interrupting application of motive fluid pressure to said actuator means when the end of the wire exits from the die means.

4. The combination of claim 1 wherein said piston actuator member separates said cylinder actuator member into first and second cylinder chambers at opposite sides of the piston actuator member, said control valve means being operative in said first position thereof to supply motive fluid pressure to one of said cylinder chambers of said hydraulic actuator means to move the draw die means in a draw stroke, said control valve means being operative in said second position thereof to interconnect said first and second cylinder chambers of the cylinder actuator member with said reservoir to l3 allow the piston actuator member to hydraulically float in said cylinder actuator member.

5. In combination with a wire processing machine operable through an operating cycle and having feed means, means for intermittently driving the feed means to advance a selectively adjustable length of drawn wire during a draw portion of the operating cycle and for interrupting advance of the wire during a subsequent dwell portion of said operating cycle, a wire drawing apparatus operable in timed relation with said processing machine to draw a length of wire during the dwell portion of said operating cycle correlative with the length of wire advanced by said feed means during the feed portion of said operating cycle, said wire drawing apparatus including a frame, a movable carriage mounted on said frame for movement toward and away from said feed means, draw die means on said movable carriage, a stationary head on said frame and wire gripper means on said stationary head between said draw die means and said feed means for gripping the wire to inhibit movement of the wire in a direction opposite the direction of advance by the feed means, hydraulic actuator means including cylinder and piston actuator members having one of said actuator members connected to said movable carriage and the other connected to said frame means, means controlled by said processing machine for supplying motive fluid pressure to said hydraulic actuator means during said dwell portion of said operating cycle sufficient to move said carriage and draw die in a draw stroke only and for interrupting application of fluid pressure to said actuator means after said carriage and draw die reach a preselected extended position to allow the draw die and carriage to dwell in their extended position until the subsequent feed portion of said operating cycle, said feed means being operative during said feed portion of said operating cycle to advance the drawn wire a selected distance and move said draw die means and said carriage and one of said actuator members with the wire in a direction away from said extended position whereby the working stroke of said actuator means is automatically adjusted in accordance with the distance the wire is advanced by said feed means and the operation of the actuator means is automatically timed with the cyclic operation of the feed means, said means for supplying motive fluid pressure to said actuator means including a supply reservoir, a pump means having an inlet communicating with said reservoir and a high pressure outlet and a delivery line connected to said outlet, flow control valve means controlling flow from said delivery line to said actuator means, check valve means in said delivery line between said pump outlet and said flow control valve means, an accumulator communicating with said delivery line between said check valve means and said flow control valve means and having a working volume which is large as compared to the volume displacement of said hydraulic actuator means, and unloading relief valve means connected to said delivery line between said check valve means and said pump outlet and operative to open and divert fluid from the pump outlet back to the reservoir to reduce the pump outlet pressure to a relatively low bypass pressure, said unloading relief valve means having means responsive to the pressure at said accumulator for opening said relief valve means when the accumulator pressure reaches a preselected maximum operating pressure and for closing said relief valve means when the accumulator pressure reaches a minimum operating pressure substantially above said by-pass pressure, and cam means controlled by said processing machine for operating said control valve means.

6. The combination of claim 1 including pneumatic pressure actuated means for yieldably biasing said carriage in the direction of advance of the wire by the feed means with a low biasing force insufficient of itself to advance said carriage and the wire engaged by the draw die means whereby to assist said feed means in advancing the wire and draw die means during said feed portion of said operating cycle, and adjustable means for regulating the pneumatic pressure applied to said pneu matic pressure actuated means to apply said low biasing force to said carriage.

7. In combination with a wire processing machine operable through an operating cycle and having feed means, means for intermittently driving the feed means to advance a selectively adjustable length of drawn wire during a draw portion of the operating cycle and for interrupting advance of the wire during a subsequent dwell portion of said operating cycle, a wire drawing apparatus operable in timed relation with said processing machine to draw a length of wire during the dwell portion of said operating cycle correlative with the length of wire advanced by said feed means during the feed portion of said operating cycle, said wire drawing apparatus including a frame, a movable carriage mounted to said frame for movement toward and away from said feed means, draw die means on said movable carriage, a stationary head on said frame and wire gripper means on said stationary head between said draw die means and said feed means for gripping the wire to inhibit movement of the wire in a direction opposite the direction of advance by the feed means, hydraulic actuator means including cylinder and piston actuator members having one of said actuator members connected to said movable carriage and the other connected to said frame means, means controlled by said processing machine for supplying motive fluid pressure to said hydraulic actuator means during said dwell portion of said operating cycle sufficient to move said carriage and draw die in a draw stroke only and for interrupting application of mo tive fluid pressure to said actuator means after said carriage and draw die reach a preselected extended position to allow the draw die and carriage to dwell in their extended position until the subsequent feed portion of said operating cycle, said feed means being operative during said feed portion of said operating cycle to advance the drawn wire a selected distance and move said draw die means and said carriage and one of said actuator members with the wire in a direction away from said extended position whereby the working stroke of said actuator means is automatically adjusted in accordance with the distance the wire is advanced by said feed means and the operation of the actuator means is automatically timed with the cyclic operation of the feed means, a second fluid actuator means connected to said carriage and to said frame means, means for applying fluid pressure to said second fluid actuator means for yieldably biasing said carriage in the direction of advance of the wire by the feed means, and means for regulating the fluid pressure applied to said second fluid actuator means to a low value to apply a low biasing force to said carriage insufficient of itself to advance the carriage and the wire engaged by the draw die means whereby to assist said feed means in advancing the wire and the draw die means during the feed portion of said operating cycle.

8. The combination of claim 1 including a set of push point grippers on said frame at the inlet side of said drawing die means selectively operable to grip the wire to hold the same against movement in a direction opposite the direction of advance of the wire by the feed means, a second control valve means connected to said hydraulic fluid reservoir and to said fluid pressure supply means and to said cylinder actuator member, said second control valve means having passage means for reversibly supply fluid to said cylinder actuator member to effect movement of said carriage and draw die means in push pointing and return strokes, and valve means for blocking flow from said second control valve means to said first control valve means during push pointing of the wire.

aw 'UNHED STATES PATENT omens (IERTEFECATE OF QQRREQTIQN Patent No. 3165L .78 r Dated April 11 1972 I e Richard A. Alcock, Robert M. Guthrie 8 Robert B. Johnston It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 13, line 27, before fluid" should be inserted motive Column 1%, line 18, "to" should be on Signed and sealed this 22nd day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. In combination with a wire processing machine operable through an operating cycle and having feed means, means for intermittently driving the feed means to advance a selectively adjustable length of drawn wire during a draw portion of the operating cycle and for interrupting advance of the wire during a subsequent dwell portion of said operating cycle, a wire drawing apparatus operable in timed relation with said processing machine to draw a length of wire during the dwell portion of said operating cycle correlative with the length of wire advanced by said feed means during the feed portion of said operating cycle, said wire drawing apparatus including a frame, a movable carriage mounted on said frame for movement toward and away from said feed means, draw die means on said movable carriage, a stationary head on said frame and wire gripper means on said stationary head between said draw die means and said feed means for gripping the wire to inhibit movement of the wire in a direction opposite the direction of advance by the feed means, hydraulic actuator means including a cylinder actuator member and a piston actuator member in said cylinder actuator member, said hydraulic actuator means having one of said actuator members connected to said movable carriage for movement therewith and the other anchored to said frame means, an hydraulic fluid reservoir, hydraulic fluid pressure supply means, control valve means connected to said reservoir and to said hydraulic fluid pressure supply means and to said cylinder actuator member, said control valve means having passage means operative in a first position of the control valve means to supply motive fluid pressure from said hydraulic fluid pressure supply means to said hydraulic actuator means sufficient to move the carriage and draw die in a draw stroke only, said control valve means having passage means operative in a second position of said control valve means to interrupt application of motive fluid pressure to said hydraulic actuator means and to hydraulically connect the actuator means to allow the piston actuator member to float axially within cylinder actuator member, means controlled by said processing machine for moving said control valve means to said first position thereof during said dwell portion of said operating cycle to supply motive fluid pressure to said hydraulic actuator means sufficient to move said carriage and draw die in a draw stroke only, means operative after said carriage and draw die reach a preselected extended position to move said control valve means to said second position thereof to allow the draw die and carriage to dwell in their extended position until the subsequent feed portion of said operating cycle, said feed means being operative during said feed portion of said operating cycle to advance the drawn wire a selected distance and move said draw die means and said carriage and said one of said actuator members with the wire in a direction away from said extended position wHereby the working stroke of said actuator means is automatically adjusted in accordance with the distance the wire is advanced by said feed means and the operation of the actuator means is automatically timed with the cyclic operation of the feed means.
 2. The combination of claim 1 including a set of push point grippers on said frame at the inlet side of said drawing die means selectively operable to grip the wire to hold the same against retrograde movement, a second control valve means operable to reversibly supply motive fluid pressure to said hydraulic actuator means to effect movement of the carriage and drawing die means in push point drawing and return strokes, and means for rendering said first mentioned control valve means inoperative to supply motive fluid pressure to said actuator means during push pointing of the wire.
 3. The combination of claim 1 including means for sensing the wire exiting from the draw die means, and means responsive to said wire sensing means for moving said control valve means to said second position thereof interrupting application of motive fluid pressure to said actuator means when the end of the wire exits from the die means.
 4. The combination of claim 1 wherein said piston actuator member separates said cylinder actuator member into first and second cylinder chambers at opposite sides of the piston actuator member, said control valve means being operative in said first position thereof to supply motive fluid pressure to one of said cylinder chambers of said hydraulic actuator means to move the draw die means in a draw stroke, said control valve means being operative in said second position thereof to interconnect said first and second cylinder chambers of the cylinder actuator member with said reservoir to allow the piston actuator member to hydraulically float in said cylinder actuator member.
 5. In combination with a wire processing machine operable through an operating cycle and having feed means, means for intermittently driving the feed means to advance a selectively adjustable length of drawn wire during a draw portion of the operating cycle and for interrupting advance of the wire during a subsequent dwell portion of said operating cycle, a wire drawing apparatus operable in timed relation with said processing machine to draw a length of wire during the dwell portion of said operating cycle correlative with the length of wire advanced by said feed means during the feed portion of said operating cycle, said wire drawing apparatus including a frame, a movable carriage mounted on said frame for movement toward and away from said feed means, draw die means on said movable carriage, a stationary head on said frame and wire gripper means on said stationary head between said draw die means and said feed means for gripping the wire to inhibit movement of the wire in a direction opposite the direction of advance by the feed means, hydraulic actuator means including cylinder and piston actuator members having one of said actuator members connected to said movable carriage and the other connected to said frame means, means controlled by said processing machine for supplying motive fluid pressure to said hydraulic actuator means during said dwell portion of said operating cycle sufficient to move said carriage and draw die in a draw stroke only and for interrupting application of fluid pressure to said actuator means after said carriage and draw die reach a preselected extended position to allow the draw die and carriage to dwell in their extended position until the subsequent feed portion of said operating cycle, said feed means being operative during said feed portion of said operating cycle to advance the drawn wire a selected distance and move said draw die means and said carriage and one of said actuator members with the wire in a direction away from said extended position whereby the working stroke of said actuator means is automatically adjusted in accordance with the distance the wire is advanced by said feed means and the oPeration of the actuator means is automatically timed with the cyclic operation of the feed means, said means for supplying motive fluid pressure to said actuator means including a supply reservoir, a pump means having an inlet communicating with said reservoir and a high pressure outlet and a delivery line connected to said outlet, flow control valve means controlling flow from said delivery line to said actuator means, check valve means in said delivery line between said pump outlet and said flow control valve means, an accumulator communicating with said delivery line between said check valve means and said flow control valve means and having a working volume which is large as compared to the volume displacement of said hydraulic actuator means, and unloading relief valve means connected to said delivery line between said check valve means and said pump outlet and operative to open and divert fluid from the pump outlet back to the reservoir to reduce the pump outlet pressure to a relatively low by-pass pressure, said unloading relief valve means having means responsive to the pressure at said accumulator for opening said relief valve means when the accumulator pressure reaches a preselected maximum operating pressure and for closing said relief valve means when the accumulator pressure reaches a minimum operating pressure substantially above said by-pass pressure, and cam means controlled by said processing machine for operating said control valve means.
 6. The combination of claim 1 including pneumatic pressure actuated means for yieldably biasing said carriage in the direction of advance of the wire by the feed means with a low biasing force insufficient of itself to advance said carriage and the wire engaged by the draw die means whereby to assist said feed means in advancing the wire and draw die means during said feed portion of said operating cycle, and adjustable means for regulating the pneumatic pressure applied to said pneumatic pressure actuated means to apply said low biasing force to said carriage.
 7. In combination with a wire processing machine operable through an operating cycle and having feed means, means for intermittently driving the feed means to advance a selectively adjustable length of drawn wire during a draw portion of the operating cycle and for interrupting advance of the wire during a subsequent dwell portion of said operating cycle, a wire drawing apparatus operable in timed relation with said processing machine to draw a length of wire during the dwell portion of said operating cycle correlative with the length of wire advanced by said feed means during the feed portion of said operating cycle, said wire drawing apparatus including a frame, a movable carriage mounted to said frame for movement toward and away from said feed means, draw die means on said movable carriage, a stationary head on said frame and wire gripper means on said stationary head between said draw die means and said feed means for gripping the wire to inhibit movement of the wire in a direction opposite the direction of advance by the feed means, hydraulic actuator means including cylinder and piston actuator members having one of said actuator members connected to said movable carriage and the other connected to said frame means, means controlled by said processing machine for supplying motive fluid pressure to said hydraulic actuator means during said dwell portion of said operating cycle sufficient to move said carriage and draw die in a draw stroke only and for interrupting application of motive fluid pressure to said actuator means after said carriage and draw die reach a preselected extended position to allow the draw die and carriage to dwell in their extended position until the subsequent feed portion of said operating cycle, said feed means being operative during said feed portion of said operating cycle to advance the drawn wire a selected distance and move said draw die means and said carriage and one of said actuator members with the wire in a direction away froM said extended position whereby the working stroke of said actuator means is automatically adjusted in accordance with the distance the wire is advanced by said feed means and the operation of the actuator means is automatically timed with the cyclic operation of the feed means, a second fluid actuator means connected to said carriage and to said frame means, means for applying fluid pressure to said second fluid actuator means for yieldably biasing said carriage in the direction of advance of the wire by the feed means, and means for regulating the fluid pressure applied to said second fluid actuator means to a low value to apply a low biasing force to said carriage insufficient of itself to advance the carriage and the wire engaged by the draw die means whereby to assist said feed means in advancing the wire and the draw die means during the feed portion of said operating cycle.
 8. The combination of claim 1 including a set of push point grippers on said frame at the inlet side of said drawing die means selectively operable to grip the wire to hold the same against movement in a direction opposite the direction of advance of the wire by the feed means, a second control valve means connected to said hydraulic fluid reservoir and to said fluid pressure supply means and to said cylinder actuator member, said second control valve means having passage means for reversibly supply fluid to said cylinder actuator member to effect movement of said carriage and draw die means in push pointing and return strokes, and valve means for blocking flow from said second control valve means to said first control valve means during push pointing of the wire. 